red and goldwere so popular from their beginnings on a Thuringian principality's state flag in 1778 that it did not seem necessary to mention them in the constitution of 1849. The flag was used for the Imperial Fleet. The short battle near Heligoland on 4 June 1849 was the first and only maritime battle in which these colours were involved. The Federal Diet had already adopted the German colours on 9 March 1848, but the Diet and also the Central Powers forgot to announce the new flag to the foreign powers. By May 1850, the flag was recognized by the US, the Netherlands, Belgium, Sardinia, the Ottoman Empire, Portugal, the Kingdom of the Two Sicilies, Spain, Greece and (conditionally) France. The reestablished German Confederation took over the fleet, but sold it in 1852 and did not make use of the German colours again until the 1860s. The German war flag, which was slightly changed twice during the Wilhelmine Period (see gallery below), was in common use in World War I. It continued to have Prussia's national colours of black and white, the eagle of Prussia, the Nordic cross, with the German imperial black-white-red tricolour in the upper canton with an Iron Cross. In 1919, the flags of Imperial Germany were scrapped and replaced by those of the Weimar Republic: a black-red-gold tricolour. German nationalists, such as the Freikorps (see Marinebrigade Ehrhardt), used the old flag in protest against the Weimar Republic during the 1920s and 1930s. This included the 1920 attempt to overthrow the Weimar government, known as the Kapp Putsch. The Nazi Party of Adolf Hitler had a party flag based on the old colours. Nazi Germany Designed personally by the new dictator Adolf Hitler, this flag served the Heer and the Luftwaffe as their War Flag, and the Kriegsmarine as its War Ensign (the National Flag serving as Jack). This flag was hoisted daily in barracks operated by units of the Wehrmacht combined German military forces, and it had to be flown from a pole positioned near the barracks entrance, or failing this, near the guard room or staff building. New recruits in the latter part of World War II were sworn in on this flag (one recruit holding the flag and taking the oath on behalf of the entire recruit class with the recruits looking on as witnesses – before, this was done on the regimental colours).